Drivers that circulate inside cities in Portugal have a maximum speed limit of 50 km/h, but the behaviour is not always in compliance with the law. After observing the possibility of high speeds in the road Avenida Almirante Gago Coutinho in Mem-Martins, Sintra, Portugal, the vehicle speed was measured with a Raspberry Pi Zero W and an exploratory data analysis was performed in R. It was verified that the vehicles moving from Mem-Martins to Sintra had a mean speed of 69 km/h and from Sintra to Mem-Martins had a mean speed of 87 km/h This road have a pedestrian crossing about 40 meters after the experimental measuring local, and two schools and a sports hall nearby that encourage the presence of many pedestrians in the sidewalk of this road.